If as a result of MA's demise my ticket now has to be rerouted, resulting in either an involuntary layover at a connection city OR in a rerouting resulting in the flown mileage to be exceeded (e.g. from a 10M to a 15M), may I expect the issuing carrier (also a OW carrier) on which the majority of the ticket was flown, to either pay for overnight accommodation or not to charge for the additional mileage?

What are the rules in such cases for any additional fuel surcharges becoming due for using alternative carriers instead of MA? Are these waived (in view of the involuntary nature of the change) or is the passenger expected to fork out?